Speckled dentifrice gel

ABSTRACT

Oral composition containing aqueous liquid and alkali metal carboxymethyl cellulose gelling agent and including non-toxic impalpable colored particles of insoluble salt of the gelling agent. The composition is formed by coloring a soluble polyvalent metal salt, such as aluminum sulfate, or soluble polyvalent metal hydroxide such as calcium hydroxide which forms a water-insoluble salt with the gelling agent, such as aluminum or calcium carboxymethyl cellulose. The dyed salt or hydroxide is then incorporated into the oral composition thereby forming non-toxic impalpable particles of the insoluble salt of the metal with the gelling agent. The speckled dentifrice may also be formed by first incorporating the metal salt or hydroxide into a dyed dentifrice gel thus permitting dye from the gel to become adsorbed into the thereby formed particles, or by incorporating the metal salt or hydroxide into an uncolored gel thereby forming particles which are themselves colored or are then dyed.

United States Patent 1 Roberts et all.

[451 Apr. 17, 1973 [54] SPECKLED DENTIFRICE GEL [73] Assignee:Colgate-Palmolive Company, New

York, NY.

[22] Filed: Jan. 11, 1971 21 Appl. No.: 105,652

Related US. Application Data [63] Continuation-in-part of Ser. No.54,635, July 13,

1970, abandoned.

[56] References Cited UNITED STATES PATENTS ll/l970 Pader et al...424/5O OTHER PUBLICATIONS Kaneniwa et al., Yakuzaigaku," Vol. 27, No.3, pages 56-60, 1967.

Primary Examiner-Richard L. Huff AttorneyHerbert S. Sy1vester, Murray M.Grill, Norman Blumenkopf, Ronald S. Cornell, Thomas J. Corum, Richard N.Miller and Robert L. Stone [5 7] ABSTRACT Oral composition containingaqueous liquid and alkali metal carboxymethyl cellulose gelling agentand including non-toxic impalpable colored particles of insoluble saltof the gelling agent. The composition is formed by coloring a solublepolyvalent metal salt, such as aluminum sulfate, or soluble polyvalentmetal hydroxide such as calcium hydroxide which forms a water-insolublesalt with the gelling agent, such as aluminum or calcium carboxymethylcellulose. The dyed salt or hydroxide is then incorporated into the oralcomposition thereby forming non-toxic impalpable particles of theinsoluble salt of the metal with the gelling agent. The speckleddentifrice may also be formed by first incorporating the metal salt orhydroxide into a dyed dentifrice gel thus permitting dye from the gel tobecome adsorbed into the thereby formed particles, or by incorporatingthe metal salt or hydroxide into an uncolored gel thereby formingparticles which are themselves colored or are then dyed.

11 Claims, No Drawings SPECKLED DENTIFRICE GEL This application is acontinuation-in-part of Ser. No. 54,635, filed July 13, 1970, nowabandoned.

This invention relates to a speckled oral composition; more particularlyit relates to a dentifrice gel which includes esthetically pleasinglycolored particles.

In the past, dentifrices have been colored in whole or in part toproduce various esthetic effects. It has been particularly desired toproduce a dentifrice containing visible or attractively coloredparticles. Such particles have often imparted characteristics to thedentifrice which may not be wholly desirable. Thus, flavor orabrasiveness may be too greatly concentrated in these particles and notsufficiently distributed throughout the dentifrice. Furthermore, suchparticles may be palpable and impart a degree of grittiness to thedentifrice which some people may find annoying.

It is an advantage of the invention that speckled or colored particlesare provided in a dentifrice, which particles are esthetically pleasingbut are without disadvantages which have been present in speckleddentifrices of the prior art. Additional advantages of this inventionwill be apparent from consideration of the following specification.

In accordance with certain of its aspects, this invention relates to adentifrice gel composition comprising a gel vehicle comprising anaqueous liquid and alkali metal carboxymethyl cellulose gelling agentand having incorporated therein impalpable non-toxic colored particlesof the water insoluble salt of carboxymethyl cellulose and a polyvalentmetal.

The polyvalent metals employed are in the form of their water-solublesalts or water-soluble hydroxides (the solubility being sufficient toenter into reaction with alkali metal carboxymethyl cellulose). Theyshould also be substantially non-toxic upon placement in the oralcavity, even though the amount of soluble polyvalent metal ion remainingafter reactionas alkali metal carboxymethyl cellulose is minimal. Thefollowmg polyvalent metals may be used:

METAL PERIODIC GROUP ATOMIC NO. Magnesium II A 12 Calcium II A StrontiumII A 38 Barium II A 56 Aluminum III A 13 Gallium III A 31 Germanium IV A32 Tin IV A 50 Lead IV A 82 Iron VIII 26 Nickel VIII 28 Zinc II B 30Cadmium II B 48 Each of these polyvalent metals is characterized asbeing selected from the group consisting of a member of periodic GroupII A having an atomic weight of 1256, Group VIII having an atomic numberof 26 and 28, Group II B having an atomic number of 30 and 48, Group IIIA having an atomic number of 13 and 31 and Group IV A having an atomicnumber of 32-82.

Metals set forth above which are capable of forming water-soluble saltsor hydroxides in two polyvalent valences, such as iron and tin may beemployed in both valence forms.

The prepared salts and hydroxides used in forming insoluble salt ofcarboxymethyl cellulose are aluminum, calcium, iron, cadmium and tin,particularly aluminum and calcium.

Dentifrices such as toothpastes which may be translucent, transparent,as well as opaque, contain a dental vehicle which forms a gel or creamymass of a consistency which can be desirably extruded from a collapsibletube such as an aluminum tube, or a lead tube.

The vehicle, often referred to as a gelled vehicle, contains liquids andsolids. In general, the liquid comprises water and/or a humectant suchas glycerine, sorbitol, propylene glycol or polyethylene glycol 400including suitable mixtures thereof. It is usually advantageous to use amixture of both water and one or two humectants. The total liquidcontent is generally about 20-29 percent by weight of the vehicle. Intransparent and translucent vehicles the liquid content of thetoothpaste may be about 20-90 percent by weight, while in opaquevehicles the. total liquid content is usually about 20-50 percent byweight. The preferred humectants are glycerine and sorbitol. Typicallyclear, that is transparent or translucent, vehicle contains 0-80 percentby weight of glycerine, about 20-80 percent by weight of sorbitol andabout 20-80 percent by weight of water. Opaque vehicles typicallycontain about l535 percent by weight of glycerine and about l0-30percent by weight of water.

The solid portion of the vehicle is a gelling agent. In the instantinvention the gelling agent includes alkali metal carboxymethylcellulose in amount of at least about 0.25 percent by weight of thevehicle. Additional gelling agents may also be present. Gelling agentswhich may be additionally present include viscarin, gelatin, starch,glucose, sucrose, polyvinyl pyrollidone, polyvinyl alcohol, gumtragacanth, gum karaya, hydroxy propyl cellulose, methyl cellulose,carboxyethyl cellulose, sodium alginate, Laponite CP or SP, which areeach synthetic inorganic complex silicate clays sold under trademwrk byLaporte Industries, LTD., and magnesium aluminum silicate gel. The solidportion or gelling agent of the vehicle is typically present in amountof about 0.25-l0 percent by weight of the toothpaste and preferablyabout 0.35-5 percent by weight. Alkali metal carboxymethyl celluloseincludes the lithium, sodium and potassium salts.

In accordance with this invention, particles are formed in the oralpreparation which are already colored at thier time of formation or aresuitable for being colored by incorporating a water-soluble polyvalentmetal salt of hydroxide, such as aluminum sulfate, calcium hydroxide,stannous fluoride, ferric sulfate, cadmium slufate and the like, in agelled dentifrice vehicle thereby forming particles which are thereaction product of the metal of the salt or the hydroxide with alkalimetal carboxymethyl cellulose. (When stannous fluoride is employed toform the particles, fluoride can also be provided to the finisheddentifrice.) The salt or hydroxide is added to the gel with agitation toform the water-insoluble particles. The particles may be long,irregular, circular, oval or other various shapes depending on thepolyvalent metal employed. When aluminum sulfate is employed, ovalshaped water-insoluble particles of aluminum carboxymethyl cellulose areformed. The metal salt or hydroxide is incorporated in the gelledvehicle in this and other techniques of the invention in amountsufiicient to react wtih at least about 5 percent by weight of thegelling agent, typically about 530 percent when alkali metalcarboxymethyl cellulose is the sole gelling agent,

and in greater amounts if additional gelling agents are present, therebyforming the impalpable non-toxic, insoluble particles of the invention.

The quantity of Salt or hydroxide added must not be sufficient todestroy the gel character of the oral composition.

If the water-soluble polyvalent metal salt or hydroxide is not dyed atthe time it is incorporated into the gelled dentifrice to formimpalpable water-insoluble particles such as particles of aluminumcarboxymethyl cellulose, then a gelled vehicle which has been previouslydyed can be employed. The dye in the gelled vehicle is absorbed on thesubstrate of water-insoluble particles thereby creating a speckledeffect. The color of the particles dyed in this manner is a deeper colorthan that of the surrounding gel and-thus desirable visual constrast isobtained. Moreover, since the absorbed dye on the particles issubstantive, the gelled vehicle can be again dyed to modify its colorand increase contrast with the particles which are not themselvesfurther dyed.

Preferably, the water-soluble polyvalent metal'salt or hydroxide is dyedbefore it is blended with the dentifrice. The gelled vehicle may beclear, translucent or opaque. in this technique the metal compound suchas aluminum sulfate is dyed by dry blending as with a mortar and pestleor more preferably by adding a solution of the dye in alcohol such asethanol, or other volatile solvent for the dye which has little solventaction on the metal compound, such as acetone. After the metal compoundis thus treated the solvent is evaporated leaving an evenly coloredcompound. The colored compound is then slowly incorporated into thedentifrice gel while agitating thereby forming dyed particles of thecarboxymethyl cellulose of the metal of the compound, such as aluminumcarboxymethyl cellulose.

If desired, the salts or hydroxides which are to be contacted with thegelled vehicles may be colored various colors and the dentifrice gelvehicle may also be dyed, thus permitting formation of a toothpastewhich has'multi-contrasting colors with an irridescent beaded effect.

Alternatively a particularly desirable esthetic dentifrice is formed bydyeing the particles with a red dye and leaving the gelled vehiclewhite.

Moreover yellow to rust colored particles are formed when thecarboxymethyl cellulose is reacted with materials such as ferrous andferric compounds. Such particles need not be dyed.

If desired the gelled vehicle may also be milled with dentifricepolishing agents, flavor and additional components of a dentifrice priorto incorporating therein the colored metal salt or hydroxide, whichcould then be mixed with the dentifrice, typically with a Hobart mixer.

The substrate of dyed particles in the gelled dentifrice vehicle areimpalpable and are easily cleared from the oral cavity followingtoothbrushing. When the particles are aluminum carboxymethyl cellulose,they are typically about 0. 1-1 .5mm in size and are generally oval inshape. when they are formed in the gelled vehicle in which polishingagent, flavor and other components have been previously incorporated,they are generally about 0.3-1.5mm in size. When they are formed in thegelled vehicle prior to addition of further components to the vehiclethey are generally reduced in size during milling with the remainingcomponents and may then be about 0. l-lmm in size.

Generally the colored particles have a Munsell chroma sufficient toimpart desirable contrast between the substrate particles and the lesscolored, white or clear gel. Of the one or more colors used for dyeingpurposes, at least one comparatively bright one should be employed tosecure attractive contrast. Upon adsorption of the dye on the metalcarboxymethyl cellulose a mordant-type dye is formed.

Individuals differ in thier response to various color stimuli but as arule bright colors will be of a Munsell value within the range of 3-8,as determined by ordinary visual examination of standard Munsell colorcharts. Not all colors with Munsell characteristics in this range willalways be useful in making distinctively speckled products. Thoseyellows of lower Munsell value within the range given which also havelower chroma within the range are drab, while those near values 7 and 8are bright, even vivid. On the other hand, darker hues such as blue,purple-blue and purple are pastels at Munsell value 8, even at somechroma above 4, but are attractive bright colors at Munsell value 3 ifof sufficiently high chroma. For most colors, if the Munsell value isbetween 4 and 7 and the chorma above 4, sufficient brightness will beobtained to allow the production of an attractively contrasting speckleddentifrice gel.

As a few examples of the most advantageous colors are given thefollowing appearing in the Munsell Book of Color, Standard Edition,Munsell Color Company, Inc., Baltimore, MD. (1929); 5 Red 4/14; 10 RedPurple 3/10; lO- Purple 4/10; 5 Yellow Red 6/12; 10 Green 5/6; 2.5Yellow 8/12; 7.5 Yellow 7/10; 5 Yellow 8/12; 10 Yellow 7/8; 5 GreenYellow 5/8; 5 Green 5/8; 5 Blue Green 4/6; 5 Blue 4/8; 5 Purple Blue3/12; 5 Purple Blue 4/10; 5 Purple 4/l2; 5 Purple 3/10; 5 Red Purple4/12.

The numeral before the hue word denotes thw specific hue. Thus 5Ydenotes a pure yellow, exactly midway between Yellow Red and GreenYellow, while 2.5Y is a hue halfway between Yellow and Yellow Red-Yellow. The fractional numeric designators are for value (numerator) andchroma (denominator).

The above listing of respresentative suitable colors indicates, as isgenerally the case, that the preferred colors are thos of higher chroma.The preferred value level is dependent to an extent upon the hueselected. Since the publication of the Munsell Book of Color, which isstill one of themost useful references for color identification, thedevelopment of fluoroescent dye materials such as D & C Red 19 and othernewer dyestuffs has made it possible to obtain colors of much greaterbrightness to the eye than those shown by Munsell. These colors may beconsidered to have higher chroma, as a consequence of which they areeven more useful for dyeing particles to give them a strong contrastagainst a background. A method of identifying and coding suchfluorescent dye and pigment products has not been universally acceptedbut one practical way of describing materials colored by them is byassigning higher chorma in the Munsell system. Red particles ofattractive color and birthgness completely colored with the fluorescentdye, D & C Red 19 contrast strongly with a white or colorless dentifricevehicle. It is highly desirable to use fluoroescent dyes of strong colorwhich yield particles of Munsell chroma greater than 10. Alternativelyfluoroescent dyes may be added to ordinary dyes to give such a brightcolor.

The hue or color may have any chromatic character. Yellow, red, green,blue and purple are all satisfactory, as are the multitudinousintermediates. White and black are less desirable, the former because itdoes not contrast with the usual light colored vehicle and the latterbecause it is inapprporiate in a product designed for cleansing teeth.Nevertheless, pure white and black are definitely useful in tinting orshading the chromatic hues to numerous intermediate colors.

Of the colors avaialbe it is preferred to use th reds, blues andpurple-blues, rather than the yellows and browns. Even the coloringagents resulting in a metallic appearance, e.g., silver, gold, may beemployed.

Methods for identifying color other than the Munsell system may also beemployed. The trichromatic coefficients of the International Commissionof Illumination, obtainable by measuring reflectance using StandardIlluminant C and prescribed filters, enable one to determine thedominant wave length and degree of saturation of a particular color andthe reflectance (Y) indicates the brightness of the color. These indiciacorrespond to the hue, chroma and value of the Munsell system. The I. C.I. method takes account of the psychophysical factor by integration ofthe responses of a normal observer by use of special filters.

Munsell standard colors have been analyzed by the I.C.I. methods and inthe literature there have been published conversion charts from Munsellto I. C. I. These charts may also be used reversibly. Prime sources ofsuch tabluations and charts are found in the Journal of the OpticalSoceity of America, Vol. 30, pages 609-616 (DEc. 1940) and J.O.S.A.,Vol. 33, pages 385-418 1943).

Although both the Munsell and I. C. 1. Systems are capable of definingcolors accurately and conversions can be made from one system to theother, it is not always possilbe to easily and simply define a broadclass of clors in one system from a description of that class in theother. In the present case the class of bright colors usually lieswithin the range of 0.12 to 0.43 in luninous reflectance (Y) but, aswith Munsell values, this may be enlarged to about 0.07 to 0.60 if theright hue is employed. A few bright colors, especially the yellows andgreens, which have refiectances a little above 0.60, are useufl eventhough outside the range of reflectances given above. Similarly, someblues and purples are also useful which have excitation purities belowpercent.

Still another method of describing color is that commonly known as theOstwald Color Triangle System. The Ostwald system, like these of theMunsell and I. C. I., analyzes color into hue (chormatic), achromaticand hue strength. The Ostwald notation is also convertible to Munselland I. C. I. figures.

No matter which of the above or other systems for identifying color isemployed the results will depend on the particular illuminant lightingthe colored surface and also to some extent upon the character of thesurface itself and the viewing angles. Most of the determinationsdescribed in this application were made by the standard method ofdirecting illuminating light at an angle of 45 to the flat color surfacealthough the equivalent reverse method is also staisfactory. Usuallydaylight viewing of color is the ultimate test, but, because daylightvaries in wave lengths a standard light source which simulates daylight,such as illuminant C, is preferably employed in all determinations.Occassionally, diffuse lighting may be found most practicable.

The particular color of the brightly colored particles is most importantin securing a distinctive speckled effect to the dentifrice composition.Of course, the color of the background gelled vehicle is also of someinfluence.

The background gelled vehicle will generally be of a light color, clearor colorless. In most cases this will be a white, near white, lightclear, colorless, although pastels also have been found to give asatisfactory contrasting product, It is preferred that the backgroundmaterial be of a shade which usually will have a Munsell value above 7and a Munsell chroma in the range 0 to 4. The background color may alsobe a white or near white or great brightness of chroma.

In the science of color measurement it is known that complementarycolors usually harmonize. Colors, which strictly speaking, are not trulycomplementary, also often are found to be perfectly harmonious when usedin the proper amounts and proportions. But as far as color contrast isconcerned, there is no fixed rule or simple scientific method forpredicting or describing it. The layman knows that color combinationssuch as blue and white, purple and yellow, red and blue, brown andyellow, green and white and many others may contrast sharply. Contrastscan also be made using hues of different values and chroma. Thus,scarlet constrasts with pink and royal blue stands out well against apastel blue background. Similarly strong bright colors contrast withpastels of other hues.

The proportions of contrasting colored materials may be varied widely,but to secure an effect considered pleasing by the average consumer thebrightly colored particles should be in the minority to providesufficient particles to be significantly discernible over at least about0.5 percent of the surface area of the vehicle. To secure still bettercontrast it is preferred that the dyed particles be discernible overbetween about 2 and 30 percent of the surface area of the vehicle.

Any suitable substantially water-insoluble polishing agent may be addedto the gel vehicle. There is a relatively large number of such materialsknown in the art. Representative materials include, for example,dicalcium phosphate, tricalcium phosphate, insoluble sodiummetaphosphate, aluminum hydroxide, magnesium carbonate, calciumcarbonate, calcium pyrophosphate, calcium sulfate, bentonite, etc,including suitable mixtures thereof. It is preferred to use thewater-insoluble phosphate sodium metaphosphate and/or a calciumphosphate, such as dicalcium phosphate dihydrate. In general, thesepolishing agents will comprise a major proportion by weight of the solidingredients. The polishing agent content is variable, but will generallybe up to about percent by weight of the total composition, generallyabout 20-75 percent; although, as indicated below, even lower amounts ofpolishing agent can be employed.

In accordance with preferred aspects of the invention the polishingagent which may be added to the gel vehicle is amorphous silicicanhydride or dehydrated silica gel polishing agent which, when employed,most preferably has an average particle size of about 2-55 microns and asurface area of about 200-450m'lg. Typical examples of such materialsare Syloid 72 and Syloid 74 which are described in The Davison Family ofSyloid Silicas published by their manufacturer, Grace, Davison ChemicalCompany, and Santucel 100, manufactured by Monsanto Company. Dehydratedsiica gels having greater surface areas, such as more than about 600m/g, such as Syloid 63, also manufactured by Grace, Davison ChemicalCompany, may also be employed. However, such materials are poorer inpolishing ability and are more abrasive to dental enamel than the agentshaving less surface area.

An additional highly desirable polishing agent which may be added to thegel vehicle is a complex sodium aluminosilicate which has a refractiveindex of about 1.44-1.47, up to about 20 percent by weight of moistureand up to about 10 percent by weight of sodium oxide. Typically, thismaterial has a particle size of up to about 35 microns, preferably about1-20 microns. The preferred moisture content is about 10-20 percent byweight, measured by loss at 105 C. and the typical content of sodiumoxide is about 5-10 percent by weight. Generally, the agent has a loosebulk density of up to about 0.2g/cc, preferably about 0.07-0.12gcc.

The amorphous silicic anhydride or dehydrated silica gel and complexsodium aluminosilicate polishing agents when present are employed inamounts of about 5-50 percent of the dentifrices, preferably about -30percent by weight.

Other polishing agents such as dicalcium phosphate and others mentionedabove may be used in transparent or translucent dentifrices in additionto amorphous silicic anhydrides in amounts up to about 10 percent of thedentifrice. Greater amounts would tend to substantially diminish theclarity of the product.

Any suitable surface active or detersive material may be incorporated inthe gel vehicle. Such compatible materials are desirable to provideadditional detersive, foaming and anti-bacterial properties dependingupon the specific type of surface active material and are selectedsimilarly. These detergents are water-soluble organic compounds usually,and may be anionic, nonionic, or cationic in structure. It is preferredto use the water-soluble non-soap or synthetic organic detergents,usually. Suitable detersive materials are known and include, forexample, the water-soluble salts,of higher fatty acid monoglyceridemonosuflate detergent (e.g., sodium coconut fatty acid monoglyceridemonosulfate), higher alkyl sulfate (e.g., sodium lauryl sulfate), alkylaryl sulfonate (e.g., sodium dodecyl benzene sulfonate), higher fattyacid esters of 1,2- dihydroxy propane sulfonate), and the like.

The various surface active materials may be used in any suitable amountgenerally from about 0.05 to about 10 percent by weight, and preferablyfrom about 0.5 to 5 percent by weight of the dentifrice composition.

It is a further embodiment of the present invention to use thesubstantially saturated higher aliphatic acyl amides of lower aliphaticamino carboxylic acid compounds, such as those having 12 to 16 carbonsin the acyl radical, and as more particularly described in US.

Pat. No. 2,689,170, issued Sept. 14, 1954. The amino acid portion isderived generally from the lower aliphatic saturated monoaminocarboxylic acids having about 2 to 6 carbons, usually the monocarboxylicacid compounds. Suitable compounds are the fatty acid amides of glycine,sarcesine, alanine, 3-aminopropanoic acid and valine having about 12 to16 carbons in the acyl group. It is preferred to use the N-lauroylmyristoyl and palmitoyl sarcoside compounds, however foroptimum effects.

The amide compounds may be employed in the form of the free acid orpreferably as the water-soluble salts thereof, such as the alkali metal,ammonium, amine and alkylolamine salts. Specific examples thereof aresodium and potassium N-lauroyl, myristoyl and palmitoyl sarcosides,ammonium and ethanolamine N-lauroyl sarcoside, N-lauroyl sarcesine, andsodium N-lauroyl glycine and alanine. For convenience herein, referenceto amino carboxylic acid compound, sarcoside, and the like refers tosuch compounds having a free carboxylic group or the water-solublecarboxylate salts.

Such materials are utilized in pure or substantially pure form. Theyshould be as free as practicable from soap or similar higher fatty. acidmaterial which tends to reduce the activity of these compounds. In usualpractice, the amount of such higher fatty acid material is less than 15percent by weight of the amide and insufficient to substantiallyadversely affect it, and preferably less than about 10 percent of saidamide material.

Various other materials may be incorporated in the vehicles of thisinvention. Examples thereof are preservatives, silicones, chlorophyllcompounds, ammoniated materials such as urea, diammonium phosphate andmixtures thereof, materials which can increase contrast with theparticles, such as zinc oxide or titanium dioxide and otherconstituents. These adjuvants are incorporated in the instantcompositions in amounts which do not substantially adversely affect theproperties and characteristics suitably selected and used in properamount depending upon the particular type of preparation involved.

Antibacterial agents may also be employed in the gelled vehicles of theinstant invention. Typical antibacterial agents includeN-(4-chlorobenzyl) N -(2,4-dichlorobenzyl) biguanide;

p-chlorophenyl biguanide;

4-chlorobenzhydryl biguanide;

4-chlorobenzhydrylguanylurea;

N-3-lauroxypropyl-N-p-chlorobenzylbiguanide;

1 ,6-di-p-chlorophenylbiguanide hexane;

l lauryldimethylammonium )-8-( p-chlorobenzyldimethylammonium) octanedichloride;

5 ,6-dichloro-2-guanidinobenzimidazole;

N'-p-chlorophenyl-N -laurylbiguanide;

S-amino- 1 ,3-bis( 2-ethylhexyl)-3-methylhexahydro pyrimidine; and theirnon-toxic acid addition salts.

The antibacterial agent, when present, is employed in amounts of about0.1-5 percent by weight, preferably about 0.05-5 percent.

Any suitable flavoring or sweetening materials may be employed informulating a flavor for the compositions of the present invention.Examples of suitable flavoring constituents include the flavoring oils,etc., oils of spearmint, peppermint, Wintergreen, sassafras, clove,sage, eucalyptus, marjoram, cinnamon, lemon and orange, as well assodium methylsalicylate. Suitable sweetening agents include sucrose,lactose, maltose, sorbitol, sodium cyclamate and saccharine. Suitably,flavor and sweetening agent may together comprise from about 0.01 topercent or more of the compositions of the instant invention.

A fluorine-containing compound having a beneficial effect on the careand hygiene of the oral cavity, e.g., diminution of enamel solubility inacid and protection of the teeth against decay may also be incorporatedin the gelled vehicle. Examples thereof include sodium fluoride,stannous fluoride, potassium fluoride, potassium stannous fluoride (SnF.KF), sodium hexafluorostannate, stannous chlorofluoride, sodiumfluorozirconate, and sodium monofluorophosphate. These materials, whichdisassociate or release fluorinecontaining ions in water, suitably maybe present in an effective but non-toxic amount, usually within therange of about 0.01 to 1 percent by weight of the water soluble fluorinecontent thereof.

The composition should have a pH practicable for use. A neutral to basicpH is particularly desirable. The initial pH range of about 4 topreferably 6-8 is considered the most practicable for use. The referenceto pH herein is intended to refer to the pH determined on the dentifricedirectly. If necessary, basic materials or acidic materials may be addedto adjust the pH as desired.

The particular pH can also affect the formation of insoluble particlesof carboxymethyl cellulose with polyvalent metal salt or hydroxide.Thus, the particles may form more readily with some metals, such as zincat the higher range of pH values. Aluminum can be used to readily formthe salt with carboxymethyl cellulose over a wide range of pH values.

Synthetic finely divided silicas such as those sold under the trademarksCab-O-Sil M5, Syloid 244, Syloid 266, and Aerosil D200 may also beemployed particularly in clear dentifrices in amounts of about 0.5-2Opercent by weight to promote thickening and to improve clarity.

The following specific examples are further illustrative of the natureof the present invention that it is to be understood that the inventionis not limited thereto. All amounts in proportions are by weight unlessotherwise indicated.

EXAMPLE 1 Aluminum sulfate is added to a sodium carboxymethyl cellulosegel which has been previously dyed with a 0.1 percent aqueous solutionof D & C Red No.19 dye. The gel also contains water and glycerine ashumectant. Insoluble red speckles of aluminum carboxymethyl cellulosewhich are oval in shape form in the sodium carboxymethyl cellulosematrix. The gel matrix is then milled with other dentifrice additives.

The gel matrix and speckles are formed from the following components:

Component Parts Glycerine 22.00 Sodium carboxymethyl cellulose 1.00 0.1%Aqueous solution of D&C Red No.19 0.1 Water 21.50 Aluminum sulfate 0.3The pH of the gel is about 6.

The additives which are added to the gel matrix are:

Additive Parts Sodium benzoate 0.50 Sodium saccharin 0.20 Sodium laurylsulfate 1.50 Alumina Trihydrate 52.00 Flavor 0.9

After milling, the speckles have a size range of about 0.1-1mm. Thespeckles are clearly visible and contrast with the backgrounddentifrice. They are impalpable and easily cleared from the oral cavityfollowing toothbrushing.

When the amorphous silicic anhydride Syloid 74 replaces 42-50 percent ofthe alumina trihydrate and sorbitol replaces glycerine, the backgroundremains clear and the colored speckles can be seen within the vehicle aswell as upon its surface.

EXAMPLE 2 The procedure of Example 1 is repeated using the followingmaterials to form the gel matrix and the speckles and as additivesfollowing formation of the gel matrix and the speckles:

GEL MATRIX & SPECKLES Component Parts Glycerine 22.00 Sodiumcarboxymethyl cellulose 1.00 0.1% aqueous solution of D&C Red No.19 0.12Water 21.23 Aluminum Sulfate 0.30

ADDITIVES TO GEL MATRIX Sodium benzoate 0.50 Sodium saccharin 0.20 Zincoxide 0.25 Sodium lauryl sulfate 1.50 Alumina trihydrate 52.00 Flavor0.90

EXAMPLE 3 Aluminum sulfate is dyed with D & C Red No.19 by dry blendingwith a mortar and pestle and is then slowly added to an agitated sodiumcarboxymethyl cellulose. Red dyed oval insoluble speckles of aluminumcarboxymethyl cellulose form instantaneously. The gel matrix andspeckles are then milled with other dentifrice additives.

The gel matrix and speckles are formed from the following components:

Component Parts Glycerine 22.00 Sodium carboxymethyl cellulose 1.00Aluminum sulfate 0.30 D&C Red No.19 0.002 Water 21.35

The additives which are added to the gel matrix are:

Additive Parts Sodium benzoate 0.5 Sodium aaccharin 0.2 Zinc oxide 0.25Sodium lauryl sulfate 1.50 Alumino trihydrate 52.0

Flavor 0.9

EXAMPLE 4 Aluminum sulfate is dyed with various colors and each coloredsalt is added to sodium carboxymethyl cellulose gels which have alreadybeen milled with other dentifrice additives thereby forming insoluble,oval red speckles instantaneously. The speckles have a size range ofabout 0.3-1 .Smm.

The complete formulation of each is:

Material Parts Aluminum sulfate 0.3 Dye 0.002 Glycerine 22.00 Sodiumcarboxymethyl cellulose 1.0 Water 21.85 Sodium benmate 0.5 Sodiumsaccharin 0.2 Sodium lauryl sulfate 1.50 Calcium carbonate 5.00Dicalcium phosphate dihydrate 46.75 Flavor 7 0.9 D&C Red No.19 and FD&CBlue No.1 are employed as dyes.

EXAMPLE 5 A clear dentifrice is formed which contains dyed visibleparticles of aluminum carboxymethyl cellulose from the followingcomponents:

Component Sorbitol 70%) 47 Glycerine 25 Sodium carboxymethyl celluloseSyloid 244 0.1% aqueous solution of DdtC Red No.19 0 Water 2 Aluminumsulfate 0. Sodium benzoate 0.5 Sodium saccharin 0.2 Sodiumaluminosilicate 1 Flavor 0.8 Sodium N-lauroyl sarcosinate The sodiumaluminosilicate employed is a complex having a refractive index of 1.46,a moisture content of about 6 percent, a mole ratio of silica to aluminaof 7:1, a sodium oxide content of 7 percent, an average particle size ofabout 35 microns and a sieved loose bulk density of about 0.07g/cc.

It will be apparent to one skilled in the art that modifications of theabove examples may be made thereto.

We claim:

1. A dentifrice gel composition wherein the gel comprises an aqueousliquid, alkali metal carboxymethyl cellulose and gelling agent havingincorporated therein impalpable, non-toxic, colored particles of thewater insoluble salt of carboxymethyl cellulose and a polyvalent metalselected from the group consisting of a member of periodic Group III Ahaving an atomic number of 13 and 31.

nuasutowleL-a.

2. The dentifrice gel composition claimed in claim 1 wherein said gelcomprises 0 to about percent by weight of glycerine, about 20-80 percentby weight of sorbitol and about 20-80 percent by weight of water.

3. The dentifrice gel composition claimed in claim 1 wherein said gelcomprises about 15-35 percent by weight of glycerine an about 10-30percen by weight of water.

4. The dentifrice gel composition claimed in claim 1 wherein saidgelling agent is present in amount of about 0.25-10 percent and saidalkali metal carboxymethyl cellulose gelling agent is present in amountof at least 0.25 percent by weight.

5. The dentifrice gel composition claimed in claim 1 wherein saidpolyvalent metal is aluminum.

6. The dentifrice gel composition claimed in claim 5 wherein saidparticles are oval and are about 0.1-1 .5mm in size.

7. A dentifrice gel composition wherein the gel comprises an aqueousliquid, alkali metal carboxymethyl cellulose and gelling agent havingincorporated therein impalpable, non-toxic, colored particles of thewater insoluble salt of carboxymethyl cellulose and a polyvalent metalselected from the group consisting of a member of Periodic Group VIIIhaving an atomic number of 26' and 28.

8. A dentifrice gel composition wherein the gel comprises an aqueousliquid, alkali metal carboxymethyl cellulose and gelling agent havingincorporated therein impalpable, non-toxic, colored particles of thewater insoluble salt of carboxymethyl cellulose and a polyvalent metalselected from the groupconsisting of a member of periodic Group II Bhaving an atomic number of 30 and 48. I

9. A dentifrice gel composition wherein the gel comprises an aqueousliquid, alkali metal carboxymethyl cellulose and gelling agent havingincorporated therein impalpable, non-toxic, colored particles of thewater insoluble salt of carboxymethyl cellulose and a polyvalent metalselected from the group consisting of a member of periodic Group IV Ahaving an atomic number of 32-82.

10. A process for producing a dentifrice gel composition comprisingincorporating a water-soluble salt or hydroxide of a salt of apolyvalent metal selected from the group consisting of a member ofperiodic Group II A having an atomic number of 12-56 into a gelcomprising an aqueous liquid and dyed alkali metal carboxymethylcellulose thereby forming impalpable, nontoxic, colored particles of thewater-insoluble salt of carboxymethyl cellulose and said polyvalentmetal.

1 l. A process for producing a dentifrice gel composition comprisingincorporating a dyed water-soluble salt or hydroxide of a salt of apolyvalent metal selected from the group consisting of a member ofperiodic Group ll A having an atomic number of 12-56 into a gelcomprising an aqueous liquid and alkali metal carboxymethyl cellulosethereby forming impalpable, nontoxic, colored particles of the waterinsoluble salt of carboxymethyl cellulose and said polyvalent metal.

0 l III v NITED S TESPATENT FFI CERTIFICATE OF-CO RRECTIQN Piatnt Nd.35728;4-6 I Dated gune i1, lQfZ llinventofls) Francis D. Roberts andJames Norfleet It is certified that error appeers in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

COLUMN 2, 13, "20-29" SHOULD READ --20-90--.

Signed and sea-led this 8th day of October 19740 (SEAL) v Attest: McCOYM. GIBSON JR. 1 c. MARSHALL DANN Attesting Officer 1 Commissioner ofPatents FORM PO-IOSO (O-69) uscom'moc eowbpe u.s. aovunuumr PRINTINGomen: Ins o-su-ss

2. The dentifrice gel composition claimed in claim 1 wherein said gelcomprises 0 to about 80 percent by weight of glycerine, about 20-80percent by weight of sorbitol and about 20-80 percent by weight ofwater.
 3. The dentifrice gel composition claimed in claim 1 wherein saidgel comprises about 15-35 percent by weight of glycerine and about 10-30percent by weight of water.
 4. The dentifrice gel composition claimed inclaim 1 wherein said gelling agent is present in amount of about 0.25-10percent and said alkali metal carboxymethyl cellulose gelling agent ispresent in amount of at least 0.25 percent by weight.
 5. The dentifricegel composition claimed in claim 1 wherein said polyvalent metal isaluminum.
 6. The dentifrice gel composition claimed in claim 5 whereinsaid particles are oval and are about 0.1-1.5mm in size.
 7. A dentifricegel composition wherein the gel comprises an aqueous liquid, alkalimetal carboxymethyl cellulose and gelling agent having incorporatedtherein impalpable, non-toxic, colored particles of the water insolublesalt of carboxymethyl cellulose and a polyvalent metal selected from thegroup consisting of a member of Periodic Group VIII having an atomicnumber of 26 and
 28. 8. A dentifrice gel composition wherein the gelcomprises an aqueous liquid, alkali metal carboxymethyl cellulose andgelling agent having incorporated therein impalpable, non-toxic, coloredparticles of the water insoluble salt of carboxymethyl cellulose and apolyvalent metal selected from the group consisting of a member ofperiodic Group II B having an atomic number of 30 and
 48. 9. Adentifrice gel composition wherein the gel comprises an aqueous liquid,alkali metal carboxymethyl cellulose and gelling agent havingincorporated therein impalpable, non-toxic, colored particles of thewater insoluble salt of carboxymethyl cellulose and a polyvalent metalselected from the group consisting of a member of periodic Group IV Ahaving an atomic number of 32-82.
 10. A process for producing adentifrice gel composition comprising incorporating a water-soluble saltor hydroxide of a salt of a polyvalent metal selected from the groupconsisting of a member of periodic Group II A having an atomic number of12-56 into a gel comprising an aqueous liquid and dyed alkali metalcarboxymethyl cellulose thereby forming impalpable, non-toxic, coloredparticles of the water-insoluble salt of carboxymethyl cellulose andsaid polyvalent metal.
 11. A process for producing a dentifrice gelcomposition comprising incorporating a dyed water-soluble salt orhydroxide of a salt of a polyvalent metal selected from the groupconsisting of a member of periodic Group II A having an atomic number of12-56 into a gel comprising an aqueous liquid and alkali metalcarboxymethyl cellulose thereby forming impalpable, non-toxic, coloredparticles of the water insoluble salt of carboxymethyl cellulose andsaid polyvalent metal. 31.